1. Technical Field
The present invention relates to a semiconductor apparatus, and more particularly, to an impedance calibration circuit and a semiconductor apparatus using the same.
2. Related Art
In order to improve an output characteristic of a semiconductor apparatus, it is very important to constantly maintain termination impedance.
That is, impedance values of various termination circuits, for example, a data output driver and so on should be matched with a target value which is set during design.
However, since the semiconductor apparatus is sensitive to a process, voltage, or temperature (PVT) variation, there is a demand for a circuit configuration capable of constantly maintaining impedance in correspondence to the PVT variation.